In 2010 we contributed to a UK government-funded project to generate carbon impacts from projects using Building Information Modelling (BIM). This resulted in a data structure and protocol for product libraries used to populate embodied carbon numbers.
BIM can provide immediate and tangible sustainability benefits through materials resource efficiency - reducing waste by using the right materials and products in the right quantities for the job.
BIM helps designers to optimise materials use by facilitating the standardisation and simplification of materials and component choices. It ensures dimensional coordination through clash detection capabilities - avoiding wasteful mistakes. Our experience at Birmingham City University, for example, involved using the BIM model to identify precise materials quantities and make life cycle comparisons between different design options.
BIM helps contractors reduce waste associated with the over-ordering of materials 'just in case', whilst promoting a more efficient construction process. Some of the evidence we are seeing indicates a reduction of at least 20%.
BIM helps building managers by encouraging sensible design choices which facilitate more efficient operation with lower maintenance and repair requirements (allowing clear life cycle analysis). It is now possible for facilities managers to monitor running costs based on real time data for energy use, maintenance and replacement intervals.
BIM also offers huge potential for the integration of a wide range of environmental performance data in the near future with clear, auditable reporting capabilities. Sustainability as a discipline needs this data to more clearly demonstrate the strong business cases for selecting sustainable design options.
BIM can provide immediate and tangible sustainability benefits through materials resource efficiency...
With increased interest in the importance of product impacts associated with our building stock (such as embodied carbon), we see the full integration of carbon data into BIM models as a relatively easy win. This should make it much more straightforward to carry out embodied carbon calculations of BIM-modelled buildings. It will also be a relatively simple jump to link energy costs to operational carbon outputs.
Beyond carbon, the EU’s CEN TC 350 provides a framework for undertaking 'cradle to grave' lifecycle assessments (LCA) for products and some manufacturers such as Phillips lighting have had their entire range assessed. This environmental data will be recognised in BIM and feed up to the project’s overall environmental rating such as BREEAM or LEED.
BIM also offers huge potential for the integration of a wide range of environmental performance data...
With water-stress becoming more pressing due to climate change, it will also be important to predict (and reduce) the potable water requirements of operational buildings. Again, this is something that BIM should easily be able to pull together based on data which is already available.
As we look further into the future, there should be options to integrate detailed energy modelling capabilities. This will allow project teams to 'tweak' their designs in order to optimise energy-efficiency.
We expect to see ‘BIM-enabled’ BREEAM assessments with the data inputted by different design team members providing direct evidence of compliance against specific BREEAM issues (e.g. materials, waste, water etc). The role of our BREEAM assessors could change significantly! It should also be possible to incorporate responsible sourcing data relating to specific products and materials (e.g. certification against environmental management systems; responsibly sourced timber etc).
Recent work by the Waste & Resources Action Programme (WRAP) has provided clear evidence of the resource efficiency benefits of BIM:
Resource use analysis of the new Leeds Arena enabled an 8% reduction in material requirement.
Design refinements at Manchester Central Library refurbishment resulted in a 50% reduction in ground slab thickness, saving 300m3 of concrete.
A recent assessment by the Gilbane Building Company identified 2,400 clashes detected during the design stage of a $51m project (estimated at $2,500 per clash).
1,800 tonnes of CO2e was saved through the use of PFA following rapid BIM analysis of the carbon impact of cement replacements on the University of Texas Health Science Centre project.